It was the moment of truth. After weeks fermenting in a 24-liter barrel, Adam Goldberg’s new beer was ready to taste. He poured a sample from the keg’s spout, inspecting its murky brown appearance through a glass.

“Not bad,” he said, taking a sip of the robust-bodied brew, which had a delicate, fruity sweetness followed by a spicy coriander-seed kick.

Mr. Goldberg, based in Hong Kong, has brewed dozens of beers, from English-style bitters to experimental concoctions made with star anise, Sichuan peppercorns and osmanthus blossoms. But he isn’t a professional. By day, he is a lawyer. By night, he homebrews, filling up the spare bedroom of his high-rise apartment with barrels of beer that churn with hard-working yeast.

“The process itself is pretty remarkable,” he said as he prepared a sterilizing solution for his bottles. “You put all these things together and it looks frothy and disgusting, and then a couple of weeks later it’s beer.”

Thirsty lager lovers and ale enthusiasts will get a chance to savor Mr. Goldberg’s latest brew Saturday, when Hong Kong plays host to its first homebrewing competition. The competition is open to anyone who has brewed beer in Hong Kong since November; Mr. Goldberg expects about a dozen contestants. Samples of each brew will be on hand for the public to judge.

Until recently, homebrewing didn’t exist in the city, but a nascent interest in craft beer among Western expats has brought more exposure to brews from the U.S., U.K. and beyond. Now more adventurous drinkers are converting their spare bedrooms into miniature breweries.

A similar story is playing out across Asia. China seems especially fertile ground for homebrewing. Last year saw the launch of the Beijing Homebrewing Society and the city’s first homebrewing festival. Gao Yan, owner of Nanjing’s Oktoberfest brewing company, sells homebrewing equipment on Taobao and wrote the first Chinese-language book on homebrewing, “Get Your Own Brew.” He estimates the number of homebrewers in China has grown to 1,200 from 200 over the past year.